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<title>GstAudioFilter: GStreamer Base Plugins 1.0 Library Reference Manual</title>
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<a name="GstAudioFilter"></a><div class="titlepage"></div>
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<h2><span class="refentrytitle"><a name="GstAudioFilter.top_of_page"></a>GstAudioFilter</span></h2>
<p>GstAudioFilter — Base class for simple audio filters</p>
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<div class="refsect1">
<a name="GstAudioFilter.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
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<tbody><tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstAudioFilter.html#gst-audio-filter-class-add-pad-templates" title="gst_audio_filter_class_add_pad_templates ()">gst_audio_filter_class_add_pad_templates</a> <span class="c_punctuation">()</span>
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<div class="refsect1">
<a name="GstAudioFilter.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
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<col width="150px" class="name">
<col class="description">
</colgroup>
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<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="GstAudioFilter.html#GstAudioFilter-struct" title="struct GstAudioFilter">GstAudioFilter</a></td>
</tr>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="GstAudioFilter.html#GstAudioFilterClass" title="struct GstAudioFilterClass">GstAudioFilterClass</a></td>
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<div class="refsect1">
<a name="GstAudioFilter.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen">    <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject-struct">GObject</a>
    <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a>
        <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstObject.html#GstObject-struct">GstObject</a>
            <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstElement.html#GstElement-struct">GstElement</a>
                <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransform-struct">GstBaseTransform</a>
                    <span class="lineart">╰──</span> GstAudioFilter
</pre>
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<div class="refsect1">
<a name="GstAudioFilter.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;gst/audio/audio.h&gt;
</pre>
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<div class="refsect1">
<a name="GstAudioFilter.description"></a><h2>Description</h2>
<p><a class="link" href="GstAudioFilter.html" title="GstAudioFilter"><span class="type">GstAudioFilter</span></a> is a <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransform-struct"><span class="type">GstBaseTransform</span></a>-derived base class for simple audio
filters, ie. those that output the same format that they get as input.</p>
<p><a class="link" href="GstAudioFilter.html" title="GstAudioFilter"><span class="type">GstAudioFilter</span></a> will parse the input format for you (with error checking)
before calling your setup function. Also, elements deriving from
<a class="link" href="GstAudioFilter.html" title="GstAudioFilter"><span class="type">GstAudioFilter</span></a> may use <a class="link" href="GstAudioFilter.html#gst-audio-filter-class-add-pad-templates" title="gst_audio_filter_class_add_pad_templates ()"><code class="function">gst_audio_filter_class_add_pad_templates()</code></a> from
their class_init function to easily configure the set of caps/formats that
the element is able to handle.</p>
<p>Derived classes should override the <a class="link" href="GstAudioFilter.html#GstAudioFilterClass.setup"><code class="function">GstAudioFilterClass.setup()</code></a> and
<a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransformClass.transform-ip"><code class="function">GstBaseTransformClass.transform_ip()</code></a> and/or
<a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransformClass.transform"><code class="function">GstBaseTransformClass.transform()</code></a>
virtual functions in their class_init function.</p>
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<div class="refsect1">
<a name="GstAudioFilter.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gst-audio-filter-class-add-pad-templates"></a><h3>gst_audio_filter_class_add_pad_templates ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_audio_filter_class_add_pad_templates
                               (<em class="parameter"><code><a class="link" href="GstAudioFilter.html#GstAudioFilterClass" title="struct GstAudioFilterClass"><span class="type">GstAudioFilterClass</span></a> *klass</code></em>,
                                <em class="parameter"><code><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> *allowed_caps</code></em>);</pre>
<p>Convenience function to add pad templates to this element class, with
<em class="parameter"><code>allowed_caps</code></em>
 as the caps that can be handled.</p>
<p>This function is usually used from within a GObject class_init function.</p>
<div class="refsect3">
<a name="gst-audio-filter-class-add-pad-templates.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
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<td class="parameter_name"><p>klass</p></td>
<td class="parameter_description"><p>an <a class="link" href="GstAudioFilter.html#GstAudioFilterClass" title="struct GstAudioFilterClass"><span class="type">GstAudioFilterClass</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>allowed_caps</p></td>
<td class="parameter_description"><p>what formats the filter can handle, as <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
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<div class="refsect1">
<a name="GstAudioFilter.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstAudioFilter-struct"></a><h3>struct GstAudioFilter</h3>
<pre class="programlisting">struct GstAudioFilter;</pre>
<p>Base class for audio filters with the same format for input and output.</p>
</div>
<hr>
<div class="refsect2">
<a name="GstAudioFilterClass"></a><h3>struct GstAudioFilterClass</h3>
<pre class="programlisting">struct GstAudioFilterClass {
  GstBaseTransformClass basetransformclass;

  /* virtual function, called whenever the format changes */
  gboolean  (*setup) (GstAudioFilter * filter, const GstAudioInfo * info);
};
</pre>
<p>In addition to the <em class="parameter"><code>setup</code></em>
 virtual function, you should also override the
GstBaseTransform::transform and/or GstBaseTransform::transform_ip virtual
function.</p>
<div class="refsect3">
<a name="GstAudioFilterClass.members"></a><h4>Members</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="300px" class="struct_members_name">
<col class="struct_members_description">
<col width="200px" class="struct_members_annotations">
</colgroup>
<tbody>
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<td class="struct_member_name"><p><a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseTransform.html#GstBaseTransformClass"><span class="type">GstBaseTransformClass</span></a> <em class="structfield"><code><a name="GstAudioFilterClass.basetransformclass"></a>basetransformclass</code></em>;</p></td>
<td class="struct_member_description"><p>parent class</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstAudioFilterClass.setup"></a>setup</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual function called whenever the format changes</p></td>
<td class="struct_member_annotations"> </td>
</tr>
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